ProAVmag

Pulling Through

Pro AV's research indicates that pulling cable and making connections and terminations probably account for the majority of billable hours on most system installation projects. 10/18/2007 9:05 PM Eastern

Pulling Through

Pro AV's research indicates that pulling cable and making connections and terminations probably account for the majority of billable hours on most system installation projects.

“It's an area that can be really difficult,” says Brad Nelson, owner of Sound Solutions Northwest in Kennewick, Wash.

It's definitely not the fun part of the job, concedes Tom Schraufnagel, design engineer for AV systems integrator ExhibitOne Corp. in Phoenix. “You get dirty, and you run into headaches. To get the job done, you've got to find creative ways around problems and still meet code.”

Nelson and Schraufnagel are talking about pulling cable, a tedious task that will remain essential to life in the pro AV industry, at least until the wireless distribution of audio and video signals becomes ubiquitous.

In fact, Pro AV's research indicates that pulling cable and making connections and terminations probably account for the majority of billable hours on most system installation projects.

This process can be tedious especially on retrofit jobs, where factors such as conduit already packed to the brim, difficult-to-cut-into walls and floors, and preservation constraints of historical buildings create continuous challenges that require clever solutions. As Nelson puts it, “Running cable in an existing building is a wild card.”

To combat common difficult wiring projects, find out how the following AV integrators pulled through some seemingly sticky situations by employing creative installation techniques.

1. CONCEAL CABLING IN FLOOR CREVICES.

THE INTEGRATOR: Joe Orlando, owner of Commercial Sound and Communication, Atwater, Calif.

THE JOB:Contracted several years ago to install a DSP-based audio system inside the 141-year-old Episcopal Church of St. Matthews in San Mateo, Calif., Orlando and his team had to figure out how to wire amps and speakers without cutting into walls and floors.

Pulling cable can be a really difficult job, says Brad Nelson, owner of Sound Solutions Northwest Inc. in Kennewick, Wash. The task accounts for most billable hours on system installation projects.

“We couldn't drill, fasten, or do anything else to this building,” says Orlando, citing the strict historical preservation guidelines for the church, which was rebuilt following the 1906 San Francisco Earthquake. “We had to be really creative in what we did. The trick, as in so many installs, was hiding the wire. You had to run in places where people wouldn't see it.”

THE SOLUTION: To wire the array of wall-mounted EAW JF-series speakers — which, fortunately, used the same mounting holes as the old sound system —Orlando's team shoved 14-gauge speaker wire into the spaces between the floorboards. “We used hot glue to keep them in place, because hot glue could be peeled off later,” says Orlando. “We also shoved foam into crevices so the wire would stay in place.”

In fact, for Commercial Sound and Communication, the marriage of problem and solution began literally at the altar, where the installation team had to mount a microphone into a large, sculpted, concrete lectern without cutting into it.

“We had to figure out how to hide the microphone, and we couldn't mount wireless microphone antennas on this beautiful sculpture,” says Orlando. Using an Audio-Technica Engineered Sound Series mic, he “brush-painted the wires grey to match [the concrete podium] and ran them down along the crevices so you couldn't see them.”

Again, heated glue was used to make the wire adhere to the cement. “I had to hide wire wherever I could,” says Orlando.

2. FOLLOW THE MOLDING AT THE BASE OF WALLS.

THE INTEGRATOR: Michael Conners, president of HomeTech Custom Design and Installation, Lincoln, R.I.

THE JOB: Dealing with older architecture also is an issue for HomeTech, which specializes in installing residential home theater and distributed audio systems. The company services many homes constructed in an era before the emergence of Sheetrock; the walls have brittle plaster covering rows of slats or metallic screen. Conners recalls a recent home project in Pawtucket, R.I. “We went through two saw blades for every speaker hole we cut,” he says. “The wall materials were very abrasive. They'd ruin all of your cutting tools. You couldn't accurately cut a six-inch [speaker] hole into them the way you could with Sheetrock, since the material would crack as you cut it. It's very hard to cut into that stuff without having to do a whole lot of patching afterward.”

THE SOLUTION: To get around cutting into these old walls while creating audio distribution systems, Conners and his team put speaker cable — almost always 16-gauge, four-conductor wire (16/4) with an associated Cat-5 cable for the control system — in the narrow gap that often exists underneath the floor molding, between the edge of the carpet and the wall.

“There is an area where the molding and the carpeting come together. If you know how, you can make very good use of it,” says Conners.

He also notes that the emergence of high-definition multimedia interface (HDMI) has made some of his home theater work particularly difficult. HDMI cables “come with a molded connector that you can't make in the field,” he says. “If you have to fish it, you will have to drill an exceptionally large hole in the wall.”

3. WHERE THERE ARE STRICT CODES, SUBCONTRACT IT OUT.

THE INTEGRATOR: Brad Nelson, owner of Sound Solutions Northwest, Kennewick, Wash.

THE JOB: Sound Solutions recently was contracted to install a new audio system in a church that's more than 100 years old, in nearby Walla Walla, Wash. While the integrator didn't encounter the same kinds of stringent historical preservation guidelines that challenged Orlando's team during its church project, the prospect of drilling into such an old building concerned Nelson, who estimates that retrofit jobs account for 50 percent to 60 percent of his company's business. “In an older building, there's much more of a chance of damage to the surface or the structure,” he says.



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Pulling Through

Pro AV's research indicates that pulling cable and making connections and terminations probably account for the majority of billable hours on most system installation projects.

THE SOLUTION: “We thought we wouldn't be the best at doing the cable runs, so we hired an electrical contractor,” says Nelson. “On larger projects, we typically don't pull our own wire. We're more than willing to subcontract out that particular task if we know a strategic partner that will do a better job.”

The particularly strong presence in Washington state of the International Brotherhood of Electrical Workers factored into this strategy, but there are other good reasons for Nelson to subcontract out cable pulls to electricians, he explains. For one, electrical contractors are more intimately familiar with Article 640 of the National Electrical Code, the part that deals with low-voltage audio systems.

“There are things in the code that govern what we do, but a lot of AV contractors aren't aware of that,” says Nelson. “They think it's just for power and lighting.”

Offsetting liability is another reason why Sound Solutions subcontracts its wirework to other vendors. At the Walla Walla church, for example, the electrical subcontractor damaged the ceiling, “and they had to bring in their insurance company to settle things with the church,” says Nelson. “It was unfortunate for them, but it was fortunate for us that we didn't run into that.”

That doesn't mean you shouldn't closely monitor the work of electrical subcontractors. “You have to communicate exactly the wire paths you want to take,” says Nelson, recalling another recent church install. “We thought the cable should run through the back wall and through the ceiling, but the electrician ran it through the front wall, which doubled the run. Not only did that create a cost issue, but with that longer length of cable run, the resistance was much more than we expected or designed for.”

Hiding loudspeaker cable in aesthetically sensitive buildings, such as the Episcopal Church of St. Matthews in San Mateo, Calif., can be a challenge. One method is to follow the lines and junctions of dark wood and trim.

Hiding loudspeaker cable in aesthetically sensitive buildings, such as the Episcopal Church of St. Matthews in San Mateo, Calif., can be a challenge. One method is to follow the lines and junctions of dark wood and trim.

Of course, there are plenty of smaller projects for which Sound Solutions pulls its own wire. To keep inventory costs in control, Nelson advises choosing a finite set of cables that will meet the widest variety of needs rather than stocking every gauge and plenum and non-plenum variety of cable imaginable. He also advises to order cable in bulk. “Take advantage of manufacturers' free shipping offers,” he says. “Oftentimes, if you order a certain amount, the shipping is free.”

4. USE EXISTING CABLING.

THE INTEGRATOR: Jeff Galatro, owner of Commercial Sound and Video, Sacramento, Calif.

THE JOB: Galatro works in a lot of government buildings that have interlocking ceiling tiles. Removing just one tile means the installer has to rebuild an entire jigsaw puzzle when the room wiring is finished.

THE SOLUTION: “I try to use as much of the existing wire in these buildings as I can,” says Galatro, noting that many government facilities he works in were wired for Ethernet capability over a decade ago using plenty of Cat-5 cable that can be repurposed. For example, video signals can be sent effectively over Cat-5 using recently introduced distribution amplifiers. “For Cat-5, the electronics to amplify and equalize signals have gotten a lot better of late,” says Galatro.

When he does have to pull cable, Galatro likes to use “old wire to pull new wire through.” This is done simply by attaching the new cable to the end point of an old one, then pulling the latter through at the other end. When pulling new wire, he also likes to use fiber-optic for anything longer than 25 feet. “With fiber, unless you destroy the wire, it's going to work, and you're not going to get any RF interference,” he says.

5. USE MORE SPACE-EFFICIENT CAT-5 CABLING.

THE INTEGRATOR: Tom Schraufnagel, design engineer of ExhibitOne Corp., Phoenix

THE JOB: Like Galatro, Schraufnagel also finds himself working in a lot of government buildings — courtrooms, specifically — with tedious-to-remove ceiling tiles and wiring conduit that includes the kind of sharp turns that fish tape and stiff fiberglass push rods can't overcome. “A lot of electricians will make bends in their flex conduit that are too drastic,” says Schraufnagel, adding that other times, the older conduit has simply become too full over the years to add wiring.

ExhibitOne's cabling work mostly is done in government buildings, such as this one at the Nuclear Regulatory Commission in Las Vegas. A lot of tedious work, such as removing ceiling tiles and wiring conduit over tough obstacles goes into these retrofits.

ExhibitOne's cabling work mostly is done in government buildings, such as this one at the Nuclear Regulatory Commission in Las Vegas. A lot of tedious work, such as removing ceiling tiles and wiring conduit over tough obstacles goes into these retrofits.

THE SOLUTION: Also like Galatro, Schraufnagel is fond of routing audio and video over Cat-5, which is skinnier and easier to pull in many cases than other kinds of cable.

“You can get it into a lot smaller spaces,” says Schraufnagel.

Instead of going through walls and ceilings, Schraufnagel will often run narrow strands of Cat-5 along decorative moldings. “We've also taken it out of the courtroom and run it in the hallways to hide it,” he says.



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